Preson involved in the project: Anna Bodzoń-Kułakowska, Przemysław Mielczarek, Piotr Suder

Project

MALDI mass spectrometry imaging is a unique tool for oocyte analysis. In this approach, a single oocyte is placed on a ITO glass. Then, it has to be covered with matrix - a low molecular weight organic compound, in an organic solvent. Matrix facilitates the desorption and ionization of molecules present in the sample. The process is caused by a hit of a laser beam. The intensity of the peak in obtained lipid profile corresponds with its amount (in comparison with different cells), and a heat map of molecule localization on the glass may be created.

MALDI analysis might be performed in positive and negative ion mode. Each of them demands a characteristic matrix (DHB (2,5-dihydroxybenzoic acid) for positive and 9AA (9-aminoacridine) for negative ion mode). Different ion modes offer the identification of various kinds of lipids. In the positive ion mode, mainly glycerophosphocholines and sphingomyelins are detected. Meanwhile, the negative ion mode is suitable mainly for glycerophosphoethanolamines, glycerophosphoserines, and glycerophosphoinositols.

During our study we are working on sample preparation for lipids analysis. This is the first step in developing mass spectrometry imaging analysis for such material as a single oocyte, and we hope that this technique brings a lot of new discoveries in the field.


Equipment

  • Dewar's (Taylor-Wharton/Worthington Technologies, USA)
  • Kriotom FSE (Thermo, UK)
  • SunCollect system for wet matrix deposition (SunChrom GmbH, Friedrichsdorf, Germany)
  • MALDI–TOF/TOF UltrafleXtreme MS (Bruker Daltonics, Bremen, Germany) due to courtesy of the Institute of Pharmacology PAN